Arc-lamp control system



May .13 19541 1,494,272

' L. E. MILLER ARC LAMP CONTROL SYSTEM Filed Nov. 20. 1919 2 Sheets-Sheet 1 WITNESSES j INVENTOR' I f g MWKEQQM w 4 A TI'ORNEYS L. E. MILLER ARC LAMP CONTROL SYSTEM May 13 1924. 1,494.272

Filed Nov. 20. 1919 2 Sheets-Sheet. 2

A TTORNE Y8 Patented May 13, 1924.

UNITED STA LORIN ELMER MILLER, 0F ALLIANCE, OHIO.

UN ARC-LAMP CONTROL SYSTEM.

Application filed November 20, 1919. Serial No. 339,521.

T 0 all whom it may oonoem:

Be it'known that I, Loam E. MILLER, a citizen of the United States, and resident of the city of Alliance, in the county of Stark and State of Ohio, have invented a new and Improved Arc-Lamp Control System, of which the following is a full, clear, and exact description.

This invention relates generally to are lamps, and more particularly to a means for obtaining effective and positive control of the arc length, and of the current passing therethrough.

In arc lamps heretofore employed, of which I am aware, one of the unsatisfactory features of the control system, is that as the resistance is brought to a maximum, the length of the arc is decreased, and it has been diflicult to control the length of the arc and the amount of current flowing therethrough to obtain the desired brilliancy of light.

One of the objects of this invention is to provide a control system which will overcome the difiiculties above noted, and which will enable the length of an arc to be advanced positively by steps, and will enable an arc of the desired length to be maintained.

A further object of this invention is to provide in an arc lamp control system, a means which will compensate for decreased arc length upon an increase of current to the are through a circuit arranged in shunt relation to an electroresponsive control means governing the movement of one of. the electrodes of the arc.

A further object of this invention is to provide in an are light control system a means enabling the length'of the arc and the current fed thereto to be efiectively controlled to obtain the desired brilliancy and intensity of light.

Still a further object of this invention is to provide a system of are light control in which a means is provided for alternately increasing the arc length, and for increas ing the current fed to the are without an increase of the arc length. v.

In'the drawings showing for example a practical embodiment of the invention, the above objects are accomplished by providing a plurality of electrodes, and an electroresponsive means connected in seriestherewith to control the movement of one of said'eledtro'des, a variable current control means being connected in series with said electroresponsive means for changing the current therein to obtain a variable arc length, a second current control means being provided to be alternately or successively effective after increase of arc length to increase the current fed to the are without increase of arc length. In the form shown, the said second current varying means includes a bank of resistances adapted to be successively connected in shunt relation, the said bank of shunt resistances in turn being connected in shunt with that part of the series circuit including the electroresponsive means and the current control means. It is thus seen that by such a system of control, the arc is advanced by positive steps, after which the current through the arc is increasedin steps, and the; arc length again increased, after which the current through the arc may again be increased without the increase of the arc length. By a system in which the arc length and current are alternately or successively increased, there may be a tendency for the arc length to decrease slightly when the arccurrent is independently being increased, but by providing a control means for alternately or successively increasing the arc length after the increase of current, any slight decrease of arc length may be compensated for, and at the sametime the arc may be increased in, length over its former position after which the current may be increased the desired amount.

In the accompanying drawings forming a part of the. specification, in which similar characters of reference designate corresponding parts in the several views.

Figure l is a view showing a plurality of are light electrodes, an electroresponsive means for controlling the movement of one of said electrodes, and a wiring diagram showing the relative arrangement of control circuits. together with a rheostat for eflecting the proper control of the arc length and current therefor.

.Figure 2 is a diagram showing a step in the system for eflecting the movement of one of. the electrodes for increasing the length of the arc. A

Figure 3 is a wiring'diagram embodying a step of the process in which the current through the arc is increased without increase of the arc length;

'--Figure'4is a." diagram showing another step in the system in which the length of the arc has again been increased.

Figure 5 is a diagram showing another step in which the current through the arc is again increased.

With reference to the drawings, showing for example a practical embodiment of the invention, suitable electrodes 1-2 are shown, an electroresponsive means 3 being provided to control the movement of one of the electrodes as for example the electrode 1. For this purpose, mechanism well known in the art as for instance the core 4, the ring 5 and a suitable connecting member6, may be employed. It is to be understood that thisinvention is not to be limited to certain details of construction, and specific circuit arrangements -'herein shown, and that the same may be varied to suit particular conditions, and individual preference In the form shown, the electroresponsive means 3 is connectedin series with the electrodes 12, a current controlling means including a bank of resistances'78 and 9 adapted to be successively arranged in shunt relation by steps, being connected in series with said electroresponsive means 3, so-that thearc length betweenthe electrodes 1-2-may be varied. In order to successively bring the resistances 7-8 and 9 connected in shunt relation, in series with the electroresponsive means 3, one end of the resistances 7-8 and 9 are connected to contacts 1011 and 12 respectively, and a pivoted arm 13 having a wiping contact 14' is provided so that upon movement of the arm 13, the wiping contact will successively engage the contacts 10, 11,-and 12 thus completing a circuit for the'resistances 78 and 9, connecting them in shunt relation to each other, which shunt resistances are in turn connected in series with theelectroresponsive means. Figure 2 shows the circuits after the rheostat arm 13 has been moved to a position in which the wiping contact 14 covers the first three contacts 10, 11 and 12. The value of the resistances 7, 8 and 9 are such that for the first three steps,the length of arc and the current fed thereto will be increased gradually by steps. It is-to be noted that while a resistance is inserted, to efiect an increase of current, thatthe resistances aresuccessively introduced in shunt relation,-thus decreasing the effective tetalresistance, which in turn permits an increase of current. The circuit for the arc control system when the wiping contact. 14 covers the first three'contacts, is represented diagrammatically inFigure 2, and is traced from the line terminal 15, through the conductor 16, the arm 13, wipingcontact 14,- to the contacts 10, 11, and

- 12through the shunt resistances7, Band 9 respectively, conductor 17, rheostat ternnnal 18,.conductor 19 theiwinding of the electroresponsive means 3, conductor 20, electrodes 1 and 2 and the arc therebetween, conductors 21, rheostat terminal 22, conductor 23 to theother line terminal 24.

In the form shown, the rheostat is provided with other contacts 25, 26, 27, 28, 29 and 30 connecting with other resistances 31, 32,33, 34, 35 and 36 respectively, the function and connection of the various resistances later appearing. It is to be understood however that this invention is not limited to the character-of the rheostat and contacts, or the particular number of resistance units employed, but that the invention relates more particularly to the method of connecting and the relative sequence in which they become effective. It is to be noted that in the form shown, the wiping contact 14 is of such a length that a circuit is successively completed through the respective contacts, and that the circuit is maintained until the arm is again withdrawn. In the form shown, asuitable handle 37 is provided for the arm 13, which is pivotally mounted on a suitable bearing at '38. r

After the electrodes 12 have been separated, in order to increase the current through the are without increasing the arc length, a second current control means comprising in the form shown, a. bank of resistance elements 31, 32 and 33 having one end thereof connected with the respective contacts 25, 26 and 27, the other ends of the resistances-being brought into electrical contact so that when the wiping contact 14 is moved to contact successively with the contacts 25, 26 and 27, the resistance elements are by steps brought into shunt relation thus gradually reducing the effective resistance in the direct or primary'circuit, and permitting an increase of current to flow through'the electrodes 1, 2 with which they are connected inseries. A diagram representing the connections with the wiping contact 14 embracing the first'six contacts, is

represented diagrammatically in Figure 3. It is to be noted that the second current control means while connected in series with the arc, is connected in shunt relation with a part of a series circuit including the first current control means comprising the shunt resistanceelements 7, 8and 9, whichare connected in series with the electroresponsive device 3. .It'is to-be understood that the values of the various resistance elements may be varied to suit conditions. It has been found in practice, that under certain conditions when the current is increased to the arc by means of the second current control. means, that there is a tendency for the length .of the arc to decrease. V H

vAs a means of compensating for any decreased arc length,and to-increase the length ofthe area desired amount, the currentto the electroresponsive device 3 is increased after the operation of the second current control means for the arc has functioned. Figure 4, represents diagrammatically a condition of the circuits to effect this result, in which another resistance element 34 connected to the contact 28 has been inserted in shunt with the first named current control means including the resistances 7, 8 and 9.

If it is desired to further increase the current through the are without eflecting an increase of the arc length, other resistance elements 35, 36 connected with the contacts 29 and 30, are successively brought into shunt relation with the other shunt resistance elements 31, 32, 33 of the second current control means, thus further reducing the effective resistance in series with the arc and produce an increase of current thereto. Figure 5 represents in diagrammatical form, the arrangement of the circuits when the wiping member 14 spans all of the contacts. It is to be noted that as the wiping member 14 successively engages the contacts, that the arc length and the current "fed thereto, are successively controlled by alternately increasing the current fed to the electroresponsive means elfecting an increase of the arc length, and by increasing thecurrent fed to the arc independent of the electroresponsive means without increase of arc length. One of the important features of such a system of control, is that the arc length may be held practically constant at a predetermined length, and the current values passing through the are varied for the different positions.

It is to be understood that the number of resistance units and the values thereof may be varied as desired to suit particular conditions, and that while a certain practical embodiment of the invention has been shown, various changes and modifications may be made thereof without departing from the spirit and scope of this invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. An arc lamp control system comprising electrodes, an electroresponsive means having one terminal thereof electrically connected with one of said electrodes and being adapted to control the movement of the said one electrode in respect to the other electrode, a bank of resistances electrically connected at one end tothe second terminal of said electroresponsive means, an additional resistance electrically connected at one terminal to said one electrode, means for connecting the second electrode to a source of electric current supply, and means adapted to be electrically connected with the source of current supply and being operable at will to progressively connect resistances of said bank in series with the electroresponsive means and the electrodes and in shunt relation with one another and to connect the second named resistance in series with the electrodes and in shunt relation to the elec troresponsive means.

2. In an arc lamp control system, the combination with a pair of electrodes and electro-responsive means connected electrically to one of said electrodes and connected mechanically to said one electrode for es tablishing an arc when the electro-responsive means is energized, of a switch having a pivoted arm provided with a wiping contact adapted to be connected electrically with a source of electric current supply and a series of stationary contacts with which the wiping contact is adapted to cooperate, means for connecting the second electrode electrically to said source of current supply, a plurality of parallel resistances electrically connected with the electro-responsive means, the respective resistances being connected with successive stationary contacts of the switch beginning with the first stationary contact of the series, and other parallel resistances connected electrically with the first electrode and respectively connected with corresponding stationary contacts of the switch, whereby upon progressive movement of the switch arm the first resistances will be successively connected in shunt relation to one another and in series with the electro-responsive means, the electrodes and the switch, and the second resistances then will be connected in shunt relation to one another and in series with the electrodes and the switch.

3. An arc lamp control system comprising electrodes, an electroresponsive means having one terminal thereof electrically connected with one of said electrodes and being adapted to control the movement of the said one electrode in respect to the other electrode,

resistance means comprising a group of resistances electrically connected to the second terminal of the electro-responsive means and a second group of resistances electrically connected to said one electrode, means for connecting the second electrode to a source of electric current supply, and means adapted to be electrically connected to the source of current supply and being operable at will to connect the resistances of said re sistance means in shunt relation in respect to one another, resistances of the two groups being brought alternately in circuit with the electrodes.

LORIN ELMER MILLER. 

